1. Field of the Invention
The present invention generally relates to input devices and, more particularly, to an input device for use in an electronic device such as a mobile phone or a PDA (personal digital assistant).
2. Discussion of the Related Art
With the rapid development of communication technology, mobile phones have become a commonplace tool for communication in people's lives. In addition, because of the use of memory cards and memory sticks to boost memory, and because of the increasing convenience with which mobile phones can connect to the internet, mobile phones are increasingly being used as portable game devices. Mobile phone games have become a popular way of passing the time, especially when waiting for a meeting or stuck in traffic. Most games require the player to operate the keys of controls quickly and with precision. However, with only very small sized keys and small distances between the keys, mobile phones are not very suitable as game playing devices. The inconvenience of operating the keys reduces the fun of playing games. Therefore, an input device which can be operated quickly and can be conveniently used with the mobile phone is needed.
Referring to FIG. 1, a typical input device includes a front panel 112 and a control board 114. Two side boards 113 are vertically formed on two ends of the front panel 112. A hole (not labeled) is defined in the center of the front panel 112. Four projections 115 are formed on the control board 114 respectively adjacent to the four edges of the control board 114, and a joystick 116 is formed on the control board 114 opposite to the projections 115. The joystick 116 runs through the hole of the front panel 112. Catching mechanisms 117 are formed on the side boards 113 for locking the input device onto a mobile phone or other electronic device.
Without any resetting mechanism, the above-described input device cannot reset automatically (i.e. return to a central position) after being pressed. Therefore, the input device does not satisfactorily meet the demands of consumers for an easy-to-use input mechanism.
What is needed, therefore, is an input device which can easily be operated and is able to reset automatically.